The invention relates to a drying apparatus with a base, which has a drying area, surrounded by a sealing surface, for receiving a substance to be dried and in particular a gel, and with a cover, whose marginal area can be placed in vacuum-tight manner on the sealing surface and the drying space formed between the drying area and the cover can be evacuated.
Drying apparatuses of the aforementioned type are known and are e.g. used as desiccators in the chemical industry. Such desiccators are made from glass, the sealing surface of the apparatus base and the marginal area of the support being constructed as ground joints which are complimentary to one another and form a vacuum-tight connection, especially after being treated with grease. However, the sealing function in the vicinity of the sealing surface is very prone to contamination and consequently there is a risk of vacuum breakdowns, especially when there are low over-pressures in the drying space.